1. Field of the Invention
The present invention relates to an electronic apparatus and more particularly to an electronic apparatus having an electrostatic capacity type touch switch.
2. Description of the Related Art
Conventionally, in electronic apparatuses such as lighting systems, there are known electronic apparatuses which incorporate touch switches (for example, Japanese Unexamined Patent Publication No. 2007-55551). In such electronic apparatuses, electrostatic capacity type touch switches are also provided in a peripheral portion of an electronic apparatus so as to detect a touch thereon. For example, FIG. 17 is an explanatory diagram showing a schematic configuration of a conventional electronic apparatus 100. An upper diagram shows a perspective view which depicts an overall configuration of the electronic apparatus 100, an intermediate diagram shows a perspective view which depicts a front case 101 of the electronic apparatus 100, and a lower diagram shows a perspective view which depicts a rear case 102 and a substrate 103 of the electronic apparatus 100. In addition, FIG. 18 is a sectional view taken along the line XII-XII in FIG. 17, and FIG. 19 is a sectional view taken along the line XIII-XIII in FIG. 17.
The electronic apparatus 100 shown in FIG. 17 has a front case 101, a rear case 102 and a substrate 103 which is encompassed in these cases 101, 102. A touch switch 200 having flexible substrates 201 is mounted on one edge portion of the substrate 103. Touch switches 300 each having sensor portions 301 which are placed directly on the substrate 103 are mounted individually on the remaining three edge portions of the substrate 103.
For example, in the case of the touch switch 200 shown in FIG. 18, the flexible substrate 201 is connected to a connector 203 provided on a rear surface of the substrate 103. Then, the flexible substrate 201 is curved from the one edge portion side towards a front surface side of the substrate 103 to be brought into contact with the front case 101. A sensor portion 202 of the touch switch 200 is provided at the contact portion between the portion of the flexible substrate 201 and the front case 101. By doing so, when the one edge portion of the front case 101 where the touch switch 200 is provided is touched by the finger or the like, the sensor portion 202 reads a change in electrostatic capacity and detects that the touch switch 200 has been touched.
In addition, in the case of the touch switch 300 shown in FIG. 19, the sensor portions 301 placed on the front surface of the substrate 103 are pressed by a projecting portion 302 provided on an inside of the front case 101. By doing so, when any of the three edge portions of the front case 101 where the touch switches 300 are provided is touched by the finger or the like, the sensor portion 301 reads a change in electrostatic capacity via the projecting portion 302 and detects that the touch switch 300 has been touched.
Incidentally, in the case of the touch switch 200 utilizing the flexible substrates 201, in the event that the electronic apparatus is made smaller in size or in the event that inner surfaces of lateral end portions or lateral end corner portions of the front case 101 are formed orthogonal or a boss or a rib is formed on the inner surfaces, it is difficult to bend the flexible substrate 201 so that the sensor portion 202 is affixed to the front case 101 at the time of assemblage of the electronic apparatus 100.
In addition, in the case of the touch switch 300 having the sensor portions 301 which are placed directly on the substrate 103, although the touch switch 300 is more advantageous than the touch switch 200 which utilizes the flexible substrates 201 in terms of suppressing the production costs, the lateral end portions of the front case 101 do not face the sensor portions 301, and moreover, a large air layer 303 is interposed between the lateral end portions and the sensor portions 301. Therefore, what is actually occurring at the lateral end portions of the front case 101 is a remarkable reduction in sensitivity.
Additionally, in the event of an electrostatic capacity type sensor being used as a touch switch, a non-conductive material such as a resin is generally used as a material for a case of an electronic apparatus.
In the event of a resin being used as a material for the case, compared with a case where a metallic material is used for the case, static electricity is generated and easily enters the interior of the electronic apparatus. As this occurs, static electricity is applied to electronic components residing in the interior of the electronic apparatus, leading to a fear that the electronic apparatus malfunctions or is damaged.
Further, in the event of the resin being used as the material of the case, a shield layer has had to be provided to prevent the emission of unnecessary radiation noise to an outside of the electronic apparatus which is emitted from a high-frequency circuit portion which resides in the interior of the electronic apparatus.